Age hardening

The changes that takes place in a steel after its final treatment at normal temperatures. The changes are slow and gradual and increase the hardness, elastic limit and tensile strength of the steel. It also results in a loss of ductility.

Aging

Spontaneous changes occurring in the physical as well as mechanical properties of low carbon steel. If steel is subjected to elevated temperatures the aging process will be accelerated.

Air cooling

The method of letting a metal cool down in open air after the process of annealing or other heat treatment. When air cooling is used, no stacking is involved.

Air hardening steel

Steel that contains enough carbon and other alloying elements that allow it to be hardened in temperatures above its transformation range. This creates a martensitic steel structure without the steel going through the process of quenching.

AISI

The American Iron and Steel Institute that is a North American trade association. It has 50 member companies as well as 100 associate members representing America, Canada and Mexico.

AL

Chemical symbol for aluminum. In the steelmaking process, aluminum is used as an alloying agent to efficiently deoxidize steel, restricting grain growth and it is an alloying element in nitriding steel.

Alloy steel

Refers to steel that has a substantial content of elements other than carbon and the generally accepted levels of manganese, sulfur, silicon and phosphor. These elements are added to raise the strength, hardness or chemical resistance of the steel.

Alloy Surcharge

A supplementary charge added to the selling price of steel in order to offset price increases in raw materials used in the manufacture process such as nickel, chromium and molybdenum. The surcharge is calculated using raw material prices on certain accepted exchanges like the London Metals Exchange.

Alloying element

Metallic elements added during the steel production process to enhance particular properties of the steel. The most common elements used in stainless steel are molybdenum, chromium and nickel.

Annealing

A process wherein the steel is heated to a temperature and after this temperature is maintained for a certain time, the steel is cooled at a suitable rate. This is done in order for the steel to reach the desired microstructure and properties as well as to reduce the hardness of the steel. The heating is usually done to over 1, 900 degrees Fahrenheit, followed by a rapid cooling process.

Anodic protection

A method of corrosion control that promotes passivity by polarizing the steel to a more oxidizing potential.

Argon-oxygen decarburization (AOD)

The process as well as the vessel used to further refine stainless steel by lowering the carbon content. A mixture of nitrogen, oxygen and argon as well as some other gasses are blown into the metal and this reacts with the carbon oxygen to create an ideal mixture of steel and slag and allows impurities to be removed. The AOD is very similar to the electric arc furnace but operates at lower temperatures and also has a shorter operating period.

Austenite

Austenitic steel

This is an alloy steel with primarily an austenitic structure at room temperature. It is a non-magnetic stainless steel with a chromium content of between 16 to 30 percent and a nickel content of 4 to 28 percent. Austenitic steel has excellent ductility, formability, is very resistant to corrosion and has good weldability. It is the stainless steel grade that is most widely used.

Automatic gauge control

The hydraulic roll force system used by steelmakers to automatically calculate and adjust the thickness of the steel sheet while it is moving through the mill.

B

Bars

A finished product formed into long shapes using billets. Bars can either be hot or cold rolled and come in flat, round, hexagonal, square and octagonal form.

Beams

Squared off long products shaped in either H or I form used in the construction of buildings. It is usually stainless steel.

Bend test

The bending of steel to test its ductility and malleability. The test is usually conducted by bending the steel through 135 of 180 degrees and the radius varies depending on the steel grade and thickness. The steel is then evaluated and checked for cracking to determine if it will be passed or not.

Billet

Semi-finished long product used to form long products such as bars and wire using the process of hot rolling, casting or forging. The billet is between two and seven square inches big and usually smaller than bloom.

Blast furnace

A large cylindrical smelting furnace lined with heat resistant bricks and used to produce pig iron. It operates at around 1, 500 degrees Celsius and uses iron ore, coking coal and limestone as raw materials. The pig iron produced is used as raw material for wrought iron.

Bloom

Semi-finished long product used to form long products. Similar to a billet with the main difference being size. The cross section of a bloom is bigger than 36 square inches.

Bright annealing

The process of surface treating stainless steel in order to achieve a bright mirror-like finish. This is usually done in a controlled atmosphere or in a vacuum using nitrogen, hydrogen or cracked ammonia gasses.

Brinell hardness

Method used to test the hardness of metals. A hardened steel ball is put under pressure to make an indentation in the steel. The indentation is then measured by a microscope and given a Brinell hardness value or number (BHN).

C

Carbon steel

Refers to a common or ordinary steel that has a carbon content of up to about 2 percent and contains no other alloying elements.

Casting

The process of steelmaking where molten liquid metal is poured into a mold to produce continuously cast slab products or ingots.

Chemical treatment

The application of a chemical substance to steel surface to enhance oxide formation resistance as well as corrosion.

Chloride stress corrosion cracking

Occurs due to a combination of tensile stress and corrosion as a result of the presence of water and chloride.

Chromium

Cladding

The coating of a lower-alloy steel with a stainless steel coating by pouring, welding or coating. This raises the steel’s corrosion resistance at a lower cost.

Coil

A continuous strip of flat rolled steel that has been forced around a mandrel and then wrapped around itself in cylindrical form. This process allows longer lengths of metal to be processed, transported or stored.

Coke

Coke is used to fuel blast furnaces and is a solid carbonaceous residue sourced from low ash, low sulfur bituminous coal.

Cold-rolled non-grain oriented silicon steel (CRNGO) : Semi Processed

Semi processed CRNGO is used to manufacture commercial power frequency devices. It provides the customers the method to use their proprietary heat treatment processes to obtain desired core-loss and permeability characteristics. This method can help clients to cut cost.

Cold-Rolled Non-Grain Oriented silicon steel (CRNGO): Fully Processed

Non-oriented electrical steels are silicon steels. magnetic properties are practically the same in any direction of magnetism in the plane of the silicon steels.

Continuous casting

Making steel by pouring steel into billet, bloom or slab form directly from the furnace. The drying process lasts only minutes compared to the hours when steel is made from ingot form.

Corrosion

Environmental, chemical or electrochemical forces causing deterioration in a metal. Corrosion can also be caused by other factors.

Corrosion resistance

The ability of a metal to resist corrosion in certain corrosive environments.

D

Die casting

Casting non-ferrous molten metals into molds or die to form the desired shape.

Ductility

The physical property of a steel being able to be formed, shaped or permanently altered without fracturing at room temperature.

E

Edge rolling (Edge conditioning)

The smoothing rolled steel strip edges as well as removing any burr. This makes it safer for the customer to manipulate.

Electric arc furnace

A steelmaking furnace using electricity to create an arc between the electrodes to melt steel or other materials. It usually has 3 graphite electrodes present.

Erosion

The depletion or degeneration of a metal surface as a result of fluid or air particles, or a combination of both, passing over the surface and causing damage.

F

Ferroalloy

A metal raw material product like ferromanganese, ferrochrome or ferrosilicon, often used in steelmaking. This product will usually contain iron as well as other metals that is useful in different stages of the steelmaking process such as the deoxidation and desulphurization stages as well as aiding in the strengthening process.

Ferrous

Metal that primarily consists of iron.

Filler metal

A third metal added during the welding, brazing or soldering phase that usually has a different composition from its parent metals.

Finish

The final appearance or condition of the metal surface. Examples of stainless steel surface finish: No 1, 2B, No 8 and more.

G

Galvanized steel

A steel that has been coated with a thin layer of zinc in order to provide better corrosion resistance. Used in garbage cans, storage tanks, underbody auto parts and more.

Gauge

The thickness of certain steel. In high quality steel, the gauge will be consistent throughout the steel to avoid the forming of weak spots.

Grain

The individual crystal units that make up the metal. The point where individual crystal units meet is referred to as the grain boundary.

H

High carbon steel

Steel with a carbon content of at least 0.3 percent. As the carbon content rises, the steel becomes less malleable and more difficult to utilize. Usually used in high wear applications such as plow blades and shovels.

High strength/low alloy steel

Steel that contains less than 5 percent strengthening or hardening alloys like nickel, chromium, silicon or manganese.

I

Ingot

A semi-finished steel product that has been solidified after being poured into molds. The molds are removed and the ingot is rerolled. Its popularity has dropped and is being replaced by continuous cast slabs.

Inside diameter (ID)

The measurement of the diameter of the hole in a pipe excluding the wall thickness. In coil terms it refers to the measurement of the hole formed when it was rolled around the mandrel.

Iron ore

Iron rich mineral used in the manufacture of steel. Iron content is usually around 55 to 65 percent.

J

K

Killed steel

Steel that has been deoxidized during the stage when the molten metal is poured into the ingot mold. This prevents the carbon and oxygen reacting to each other when the metal solidifies. Aluminum, ferrosilicon or manganese most frequently used as deoxidizing agent.

L

Ladle

Metal receptacle or container used to transport and pour molten metals.

Long Products

Low carbon steel

Steel with a carbon content of between 0.10 and 0.30 percent making it a ductile steel and easy to stretch for use in automotive parts.

M

Martensitic

Category of magnetic steel. Usually has a chromium content of 12 percent and low nickel levels as well as moderate carbon levels.

Martensitic stainless steel

Martensitic stainless steel is usually 400 series containing between 10 and 20 percent chromium and more than 0.8 percent carbon with very little to no nickel. Heat treatment is used to harden the steel.

Mechanical properties

Properties that reveal the elasticity or inelasticity of a material when force is applied. The mechanical properties of a material depend on the microstructure of the material and determines the tensile strength, yield strength as well as the hardness of the steel and more.

N

Nickel (Ni)

Used as an alloying agent in the stainless steel manufacturing process to increase the steel’s corrosion resistance and ductility.

Nickel-based superalloys

Alloy metal that is produced specifically for use in applications of high performance and high temperatures. Includes nickel-iron-chrome alloys and nickel-iron alloys.

Non-ferrous metals

Metal or alloys in that has no significant iron content.

O

Ore

Material containing iron and used in blast furnaces.

Oxidation

The chemical reaction when oxygen reacts with another element or elements. The result of oxidation is rust or corrosion. Stainless steel has a thin layer of chromium oxide that helps in the prevention of oxidation.

P

Pickling

The removal of scales or oxides from the surface of a steel with the use of chemical or electrochemical reactions. The most frequently used method is by dipping the steel in an acid bath or spraying the surface of the material with acid.

Pig iron

Molten iron produced in a blast furnace. Has a minimum carbon content of 1.5 percent. Pig iron is very brittle due to its high carbon content and is not used as a finished steel, but as a raw material. Name originated when the molten steel was poured into sand holes and solidified looking like suckling piglets.

Preheating

Heating that is applied before other thermal or mechanical treatments. This is done in order to get rid of moisture as well as for the prevention of thermal shock.

Q

Quarto Plate

Used in shipbuilding, boilers, construction, pipeline

Quenching

Process of rapidly cooling down metals. Usually done by dipping metal in water or oil and is done in order to obtain the required properties.

R

Reinforcing bar (Rebar)

Steel bar used for reinforcement of concrete in buildings and highway construction.

Rod

Semi-finished product manufactured using a billet. Is usually used to produce wire products, bolt or nail.

S

Scrap

Discarded steel that can be recycled for re-use without loosing its properties. Scrap material is usually melted and refined in order to be reclaimed. High value metal scrap such as stainless steel is very valuable and some 90 percent of new scrap is made from recycled scrap.

Secondary steel

Steel being sold at a discounted rate after it has been rejected by original customer due to a defect in surface quality, gauge or in the steel’s chemistry.

Semi-finished steel

Products including billet, slab and bloom that requires further rolling and processing before being classed as a finished product.

Slab

Semi-finished steel product used for the manufacture of rolled steel products such as sheets, plates or strip. Slab is made from ingot or by casting and will then be used to make the finished product. Is usually between 30 and 85 inches wide and 20 feet long.

SRE Flat Bar

Temper

Refers to the hardness or toughness of a metal produced using either thermal treatment or heat treatment and quenching or cold working or a combination used to create the specified consistency. The temper system varies between the steel group.

Tensile strength

The breaking strength of material when subjected to stretching forces. Measuring the strength needed to stretch and break wire rod for example. Is generally measured in pounds or tons per square inch.

U

Unified Numbering System

System that is maintained by the American Society for Testing and Materials (ASTM) and the Society of Automotive Engineers (SAE) to identify different steel grades.

V

Vacuum oxygen decarburization

The addition of oxygen to unrefined, molten steel in a vacuum in order to reduce its carbon content. A vacuum pump is used to evacuate all escaped and undesirable gasses. After this process the steel is further defined by adding additives and alloys.

Virgin melt

The production of steel with original alloys and ores, using little or no scrap in the process.

W

Width

Lateral measurement or dimension of rolled steel. During rolling process the width is not controlled and has to be trimmed to desired width after rolling.

X

Y

Yield strength

Yield strength is the stress at which a material begins to plastically deform to be permanent strain. Material will elastically deform and return to original shape just before reaching yield point when stress is applied.